Nabin K. Malakar, Ph.D.

I am a computational physicist working on societal applications of machine-learning techniques.

Research Links

My research interests span multi-disciplinary fields involving Societal applications of Machine Learning, Decision-theoretic approach to automated Experimental Design, Bayesian statistical data analysis and signal processing.


Interested about the picture? Autonomous experimental design allows us to answer the question of where to take the measurements. More about it is here...


I addition to the research, I also like to hike, bike, read and play with water color.

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Friday, March 28, 2014

Presenting in Machine Learning Conference in NYAS today

Creating High-Resolution Climate Meteorological Forecasts by Application of Machine Learning Techniques

Nabin Malakar, PhD, Emmanuel Ekwedike, BS, Barry Gross, PhD, Jorge Gonzalez, PhD, and Charles Vorosmatry, PhD
The City College of New York, New York, New York, United States;

In order to study the effects of global climate change on a regional scale, the low resolution GCM forecast data needs to be intelligently adapted (downscaled) so that it can be injected into high resolution models such as terrestrial ecosystems. Our study region is the North East domain [{35N, 45N} x {-85W,-65W}]. In particular, we focus on High and Low temperature extremes within the Daymet data set, while the low resolution climatology (at 0.5 deg) MET data are obtained from the The Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP) climatology forecast database.  Although the injection of regional Meteorological Models such as Weather Research and Forecasting (WRF) can be attempted where the GCM conditions and the forecasted land surface properties are encoded into a future time slices, this approach is extremely computer intensive. We present a two-step mechanism by using low resolution meteorological data including both surface and column integrated parameters, and then by combining high resolution land surface classification parameters to improve on purely interpolative approaches by using machine learning techniques. 

Application of Machine-Learning for Estimation of PM2.5 by Data Fusion of Satellite Remote Sensing, Meteorological Factors, and Ground Station Data

Lina Cordero, MS, Nabin Malakar, PhD, Yonghua Wu, PhD,  Barry Gross, PhD,  Fred Moshary, PhD
Optical Remote Sensing Laboratory, CCNY, New York, New York, United States;

Particulate matter with dimension less than 2.5 micrometers (PM2.5) can have adverse health effects. These particles can enter into the blood streams via lungs, reach vital organs and cause serious damages by oxidative inflammations. We present our latest progress in obtaining correct estimates of PM2.5 on regional scale by using machine learning techniques. Specifically, we apply a neural network method for better describing the non-linear conditions surrounding the PM2.5-MODIS AOD while at the same time investigating dependencies on additional factors or seasonal changes.  In our local test, we find very good agreement of the neural network estimator when AOD, PBL, and seasonality are ingested (R~0.94 in summer). Next, we test our regional network and compare it with the GEOS-CHEM product. In particular, we find significant improvement of the NN approach with better correlation and less bias in comparison with GEOS-CHEM. We also show that further improvements are obtained if additional satellite information and land surface reflection, is included. Finally, comparisons with Community Multi-scale Air Quality Model (CMAQ) PM2.5 are also presented.

Using NN techniques to ingest Meteorological Weather Satellite data in support of Defense Satellite Observations

Crae Sosa, BS, Gary Bouton, MS, Sam Lightstone, MS, Nabin Malakar, PhD,  Barry Gross, PhD and Fred Moshary, PhD
The City College of New York, New York, New York, United States;

The need to observe thermal targets from space is crucial to monitoring both natural events and hostile threats. Satellites must choose between high spatial resolution with high sensitivity and multiple spectral channels. Defense satellites ultimately choose high sensitivity with a small number of spectral channels. This limitation makes atmospheric contamination due to water vapor a significant problem which can not be determined from the satellite itself. For this reason, we show how it is possible to ingest meteorological satellite data using NN to allow for the compensation of water absorption and re-emssion in near-real time

Monday, March 24, 2014

To Aspiring students looking into a PhD program

It is nice to hear about your aspirations for a PhD. I wish you all the best!
Since my background is in physics, do not be surprised if my information turns out to be different.

I recommend that you start with the following:
1. TOEFL, GRE, subject GRE requirements.
2. A short list of universities that you would like to go, and why?
Seniors and professors may be your resources for your way into these.
3. Learn about the required supporting documents such as letter of recommendation, copies of original transcripts, application fees etc to the office of graduate admission.

Once you have figured these requirements, you will know a lot on how to proceed.
Then the usual way is to send in the applications, and supporting documents. Do inquire to the admission office to learn about the appropriate procedure.

All the best! 

The following links might be useful:


Thursday, March 6, 2014

Interview with Dr. Narayan Chapagain

We are presenting an interview with Dr. Narayan Chapagain. His successful journey from the remote village of Syangja to USA has taken another leap to Nepal. He has returned to the Associate Professor of Physics position in the Tribhuvan University, with international exposure, experience and a great motivation to uplift the research activities in Nepal. He is recipient of the prestigious NASA heliophysics Jack Eddy Postdoctoral Fellowship award and author of several research papers and books.

0. Congratulations on being elected the editor of NPS. Could you please tell us a little bit about yourself? (Where did you grow up, where and when you studied etc.) Your research interest and website/URL/Linkedin etc.

Thanks Nabin ji.
I was born in a remote village from Syangja district. I had to move around 5 hours walking distance away from my village for elementary and middle school. I completed my high school from Palpa district. For the college education, I moved to Kathmandu and I completed my I.Sc. and B.Sc from Trichandra College and M.Sc. in Physics from the Central Department of Physics, Tribhuvan University. Since then, I joined as a faculty member in Physics at Patan M. Campus. I got a scholarship to study Post Graduate Courses in Space and Atmospheric Sciences organized by Centre for Space Science and Technical Education in Asia and the Pacific (CSSTE-AP) affiliated to the United Nations. I completed my Postgraduate Diploma from Physical Research Laboratory (PRL), Ahmedabad, and Master in Technology (M.Tech.) in Space and Atmospheric Sciences from Andhra University, India in 2003. In 2005, I moved to United States to peruse my further education and completed my Ph.D. in Space Physics in 2011 from Utah State University, UT, USA. I won the very prestigious Jack-Eddy Postdoctoral Fellowship Award sponsorship by NASA Living With a Star Helliophysics Program in a host institute at the Department of Electrical and Computer Engineering at University of Illinois at Urbana-Champaign, USA. After my two years of postdoctoral research experiences, I returned to my home institute, Tribhuvan University, Nepal in 2013 and I have been continuing my faculty position as an associated professor in Physics.

During my M.Sc., I was involved in theoretical research work in Plasma Physics while in my M.Tech. degree, I worked on analysing the ozone data over Kathmandu measured by both ground- and space-based observations. My present research is focused on electrodynamics of thermosphere-ionosphere, especially low-latitude ionospheric irregularities and its coupling effects on neutral dynamics. I have used optical imaging data, radar and satellite observations and modelling works as well. The webpage indicating of my activities are as follows:

1. How did you decide to study physics? Did anyone, in particular, influence you?
Physics was one of my favourite subjects during my I.Sc. classes. My determination to study Physics as my future career intensely augmented during my B.Sc. course when I became only one to pass the Physics subject in B.Sc first year among the hundreds of students from Trichandra campus by acquiring highest score in Physics throughout the country. So, my interest studying physics ought to be seeded during my I.Sc. class that became animated during my B.Sc. course.
2. What strategies did you use to be successful in college?
Education system in Nepal is quite different compared to the education system from abroad. Student’s overall quality or success is primarily determined by their percentage acquired in the annual exam. Students, who attend regular classes and intensively prepare their final exam during a couple of months, can secure a good percentage. This is the trend of most of the students in Nepal. However, I usually tried to understand the subjects in depth and think analytically and realize practically in our common sense. In addition, I used to balance my time between academics and my social life; I think that is the most important eminence required to be a successful student.
3. You have a long teaching experience. How was your experience in becoming formal student again during the PhD?
As I moved to US for my Ph.D. after 13 years of teaching experiences, I was wondering that how could I adopt as a fresh student in the university. When I joined to the university, I found many adult undergraduate and graduate students. In US, adult students also used to go to university after their job retirements or family settlements. So, I never felt any hesitation as becoming a PhD formal student and I easily adopted with the education system in US. I always used to keep me busy to prepare homework, exams and research works. In recognition of my outstanding academic performances, I was honoured by several prestigious awards and scholarships from the university.
4 What have you found to be the roughest aspect of being a physicist, if any?
I think, sometimes this can happen in the research project. When one puts an immense effort to a research project with a lot of investment of times and funding, but these all efforts will be useless if a proper result is not obtained. On the other hand, sometimes a genuine research result may not be accepted for the publication due to the biasness of the different group interest. I think this is the saddest part in this profession; however, occurrences of such cases may be very rare.
5. You are also a recipient of the prestigious Jack Eddy Postdoctoral Fellowship Award from the UCAR Visiting Scientists Program. Could you please share the experience?
Jack Eddy Postdoctoral Fellowship is a very prestigious award organized by University Corporation of Atmospheric Research (UCAR) visiting scientist program and sponsored by NASA Living With a Star Heliophysics program. The stringent selection criteria for this fellowship include outstanding research accomplishments, publications, the quality of research proposal and its impact on future research in space physics. I am proud to mention that I am one of only three recipients of this award in a global competition.
6. Do you have a favorite research paper (written by yourself or somebody else)? Could you please suggest the practical applications of your research outcomes?
There are my several favorite research papers that report on the dynamics of low-latitude ionospheric irregularities. I would like to mention one of my research papers that explains climatology of post-sunset equatorial spread F using radar observations. This paper was listed among the top five most popular papers in Space Physics published in Journal of Geophysical Research (JGR) by American Geophysical Union (ACU). The paper reports the seasonal and solar cycle variation on onset of ionospheric irregularities heights and times that is significantly important to determine the altitude of the satellite path in which GPS signal will be disrupted due to the fluctuations of radio signal that passes through the ionosphere. Improving our knowledge and understanding of the drivers of this day-to-day variability is a very active area of research in the Space Weather program and Aeronomy community due to its importance for both civilian and military communications and transportation. As space-based technologies become increasingly intertwined into our day-to-day lives and national security, it becomes paramount to understand how they can be disrupted. For example, when plasma in the ionosphere between a satellite and a receiver is turbulent, the transmitted signals scintillate similar to the twinkling of starlight as it traverses through the turbulent atmosphere. This scintillation poses a problem for a receiver, which can lose the ability to track that signal. Additionally, the structures in the ionosphere can degrade navigation solutions obtained from the Global Positioning System (GPS) beyond expected accuracies, adversely affecting technologies that rely on this system. Simulations indicate that the dynamic response can be forecasted a few days ahead, suggesting the possibility of ionospheric irregularity prediction given the right set of observations.
7. As the editor of NPS, could you please share your future plan?
So far NPS is not able to publish any standard journal of physics. My first plan is to publish NPS journal biannually and working toward peer review journal publication. To achieve this goal, we have to develop the dynamics website of NPS to publish the articles online. For this purpose, we need a financial support and expertise in the field of physics. We have a huge numbers of high skilled Nepalese Physicists around the globe, especially from USA. I believe that they are ready to contribute NPS whenever needed. So I am planning to make a proper environment and network to get a full cooperation from all physicists. I would like to propose a plan to collect financial support for NPS activities with a motto that “One-dollar per month for NPS”. A small contribution from single member will collectively make a great strength of the contribution to conduct NPS activities. I also request all Physicists around the globe to provide their feedback, suggestions and collaboration to make the NPS journal publications as a peer review.
8. What are the current challenges in Nepal for research activities? Are there short-term and long-term items, which could address the challenges?
There are several factors that affect research activities in Nepal. The current education system including elementary school to college is not suitable to prepare the students and faculties to involve in the research works. Our teaching methodology does not focus to develop the creativity skills of the students that is very crucial to generate the interest of the students in the research field. We don’t have adequate facilities and funding to carry out the research projects for the undergraduate and graduate students. The institutes responsible for research funding under the umbrella of Nepal Government, such as University Grant Commission (UGC), Nepal Academy of Science and Technology (NAST), and Tribhuvan University are suffering from politicization. The leaders of these institutes are generally appointed on the basis of their political thought rather than their academic performances. So, they are directly influenced from the political leaders and they cannot function aptly to strengthen the research activities. As a short-term plan, we have to encourage the students and faculties to make involvement in the research projects by creating a proper environment as well as providing the financial support. I believe that the universities should lead the research activities by making clear and transparent policy. Professors should be appointed and promoted on the basis of their research grants awarded, publication records, and serving as an adviser to the students for their research projects. The research institutes and universities should be autonomous and keep them out of political influences so that highly qualified and visionary leadership can get the opportunity to lead the institutes who can develop national and international collaboration for the research projects. In long term policy, structure and organization of the education system in Nepal should be changed in such a way that the students and faculties will be highly encouraged to involve in the research projects.
Perhaps, most problematic for research activities in developing nations like Nepal is the brain drain. Leaders, planners, and administrators have less interest in national development as their entire families are migrating. Nowadays, every elite and middle class family from Nepal dreams to send their children abroad for further education or training. We are heading towards a situation where there will be scarcity of intellectual minds within the country. When a society’s best and brightest people move away in pursuit of better opportunities, the country will suffer from the lack of skilled manpower for its development. Skilled and well-trained manpower is very important for the research activities and for the overall development of the country. This issue can be addressed only when there is political stability and some prospects for economic prosperity. We can initiate a project to reverse the flow by doing campaigns to lure Nepali professionals back to Nepal on short and long-term internships.
9. Sir, would you like to add anything else?
I would like to share that I am back to Nepal from United States after my PhD and Postdoctoral research experience with having a robust commitment to contribute to our nation in the field of Physics on teaching and research projects. Our huge number of high skilled manpower in Physics has been dispersed around the world, while many of them are also holding a prominence status. I would like to request to all Nepalese Physicist around the globe to contribute to our motherland in research works by their academic and financial supports. We can conduct collaborating research projects by making involvement of our manpower including students from Nepal and also by proper utilization of our resources. A small support from an individual member will collectively be a great contribution to our country that can change our society significantly.

Tuesday, March 4, 2014

Updates on Work, bibliography

Here are the latest in the line of my work at CCNY:

Bias Correction of high resolution MODIS Aerosol Optical Depth in urban areas using the Dragon AERONET Network
N Malakar, M Oo, A Atia, B Gross, F Moshary
AGU 2013 Oral Presentation in A31K (SWIRL_DA)
Injection Of Meteorological Factors Into Satellite Estimates Of Surface PM2.5
N Malakar, L Cordero, Y Wu, B Gross, M Ku
2013 EMEP Conference (, Albany, NY
Assessing satellite based PM2. 5 estimates against CMAQ model forecasts
L Cordero, N Malakar, Y Wu, B Gross, F Moshary, M Ku
SPIE Remote Sensing, 88900U-88900U-15, Germany
Ingesting MODIS land surface classification into AOD retrievals
AA Atia, A Picon, N Malakar, B Gross, F Moshary
SPIE Remote Sensing, 888707-888707-11, Germany
L Cordero, N. Malakar, Y Wu, B Gross, F Moshary
2013 CMAS Conference, NC, USA
Nabin Malakar, A. Atia, B. Gross, F. Moshary, S. Ahmed, and D. Lary
AMS 2014, Atlanta, GA, USA

Lina Cordero, N. Malakar, D. Vidal, R. Latto, B. Gross, F. Moshary, and S. Ahmed
AMS 2014, Atlanta, GA, USA

Nabin Malakar,  B. Gross, J. E. Gonzalez, P. Yang, and F. Moshary
AMS 2014, Atlanta, GA, USA

L Cordero, N Malakar,  Y Wu, B Gross, M Ku, British Journal of Environment and Climate Change 3 (4), 547-565, 2013
DOI : 10.9734/BJECC/2013/7668